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Marantz-2252-Owners-Manual

1. E 0000 nran PHONES oyeron SPEAKER systema SPEAKER Functional Block Diagram MAINTENANCE CLEANING The satin gold anodized finish of the knobs and heavy aluminum front panel will last indefinitely with proper care and cleaning NEVER use scouring pads steel wool scouring powders or harsh chemical agents such as lye solution These will mar the finish Clean with a soft lint free cloth or cotton swab slightly dampened with a mild solution of detergent and water FUSE REPLACEMENT The Model 2252 is protected by a 2 amp 250 V fuse In the event the fuse blows out replace it ONLY with a fuse of the same type and rating Replacement with a fuse of higher rating will not protect the instrument and will void the warranty IN CASE OF DIFFICULTY If the receiver and the dial lamps do not operate make sure the power cord is connected If the power cord is all right and your unit is equipped with an external AC line protector fuse check the SPECIFICATIONS GENERAL Amplifier Section RATED POWER OUTPUT MINIMUM CONTINUOUS AVERAGE POWER PER CHANNEL BOTH CHANNELS DRIVEN T se POWER BAND sc rg KTR T sien TOTAL HARMONIC DISTORTION ura r TTT r cet LOAD IMPEDANCE RATED POWER OUTPUT MINIMUM CONTINUOUS AVERAGE POWER PER CHANNEL BOTH CHANNELS DRIVEN INTO 4 OHM IMPEDANCE LOADS fuse and replace it if necessary If the dial lamps are properly illuminated but one ch
2. AltematelGhannellSelectivitVa assail ini NE NE NAN ang vaio me I tart 70 dB Spurious Response Rejection Image Response Rejection I F Rejection Balanced A M Suppression 1000 nV Stereo Separation 100 Hz 1000 Hz 10 kHz Subcamie RE CUM EAA O i ui r ST ele sates 60 dB AM Tuner Section HE Usable SensitivitY aaa 2 ra stette ia aa a 20 UV Distortion THD 30 Modulation 0 6 Signal to Noise Ratio 49 dB Frequency Response 3 dB 40 Hz 2 3 kHz Alternate Channel Selectivity 46dB Image Rejection 45dB Spurious Response Rejection A 3 50dB NEON co TOA SE ART 40 dB General RoweriReguirements valori i ra a atajar tetera ha 120 V AC 60 Hz Power Consumption at rated output both channels operating S 220 Watts idling Power Volume Control at zero vir zena e cant cis ajaga A sie wise reine esis 33 Watts Dimensions Panel Width Panel Height 440 mm 17 1 4 137 mm 5 3 8 DEDI ts TAH 365 mm 14 3 8 Weight H Re dsc tn oe NE EN a TA RE 14 kg 30 8 Ibs Packed SANE 9 narra K TE R 60 S TO SEN tea ta 17 kg 37 4 Ibs 13 SERVICE NOTES REPAIRS Only the most competent and qualified service technicians should be allowed to service the Model 2252 The Marantz Company and its factory trained warranty station personnel have the knowledge and special equipment needed for repair and calibration of this precision instrument In the event of dif
3. Peaks Pores Bak ay na a R Ma mE MERA A DAA BRE ay HERA A MS AA BRE ay HORA A PGA a EN Y HERA SA SAA A UZ BRR AA MS GA En a 7 Tea AA SAA A El ay aa A SA a ll ar saako MS AA a ll ay EER lA GA an az MIRA A MS AA NA El ay MEA A Maa a EZ MERA A MS Aa a El ay MEA A MA a EZ MEM A MS A MA EZ HERA A Ma una ll ay HERA AA MAA A El ay HERA eae a az MAA A team a ll A RCA A A mm az EER GA a EZ TEA A Bets a a 4 i e ot MA ns A ERR HA Hoesen mm El ap RCA Bee BE rr ERA am Bese EB EZ MECA b Hea EE EZ MEA dh Hak a ll ay ERA A Ma a dl ay MAA b GA mer MECA A SA A E 4 lt We Hund Getter Handbook of Instructions Model 2252 Stereophonic EER AA Fess ERB El 27 Receiver MARANTZ CO INC 20525 NORDHOFF STREET CHATSWORTH CALIFORNIA 91311 A WHOLLY OWNED SUBSIDIARY OF SUPERSCOPE INC CHATSWORTH CALIFORNIA 91311 FOREWORD For optimum performance and enjoyment from your Model 2252 Stereo Receiver please study these instructions carefully Installation and operation are not complicated but its flexibility and features deserve your becoming familiar with its controls and connections This manual is divided into two parts The first covers installation and operation in simple non technical language The second describes the 2252 in more detail with technical specifications and functional explanations For quick identification of the controls and con nections references to t
4. nents of your system This is the safest way to avoid cross connecting channels or confusing signal sources with destinations PHONO INPUTS The phono jacks are intended for use with mag netic phono cartridges and have a 47 000 ohm input impedance If a hum is heard when playing records this is an indication that the record player or its connec tions are incorrectly grounded Connect a sepa rate ground wire from the turntable or record changer from to the CHASSIS GROUND binding post of the Model 2252 If this is ineffective try reversing the polarity of the turntable s power plug If hum persists consult the instruction booklets for the turntable and or phono cartridge Figure 1 Rear Panel Connection Facilities TAPE JACKS TAPE 1 IN The pair of TAPE 1 IN jacks serve two purposes 1 By depressing the TAPE 1 MONITOR push switch signals can be played from a tape re corder set for playback mode of operation This permits playing the tape source stereo phonically or monophonically as indicated by the position of the MONO pushswitch 2 While your tape recorder is recording you can monitor the resulting tape quality by depress ing the TAPE 1 MONITOR pushswitch This requires that your recorder be equipped with separate record and playback heads and sepa rate record and playback electronics TAPE 2 IN The signals from your tape recorder connected to the TAPE 2 IN jacks can be played back when the SELECTOR switch
5. Range Dynamic Range is the ratio of input overload to equivalent input noise Input Sensitivity Input Impedance Frequency Response RIAA 20 Hz to 20 kHz Signal to Noise Ratio at rated output and 7 75 mV input High Level Aux and Tape Input Sensitivity Input Impedance Frequency Response includes power amp Signal to Noise Ratio ref to rated output and 775 mV input Output Levels Tape Out ref 7 75 mV at Phono inputs Pre Out ref 180 mV at Aux inputs ref 500 mV at Aux inputs main amp disconnected Output Impedance Tape Out Pre Out FM Tuner Section Sensitivity IHF Usable IHF 50 dB Quieting mono stereo Quieting Slope Mono RF Input for 30 dB Quieting Quieting at 20 dBf 5 5 uV 25 dBf 10 uV 40 dBf BB uv 65 dBf 1000 uV Quieting Slope Stereo Quieting at 30 dBf 17 uV 40 dBf 55uV 50 dBf 173 uV 65 dBf 1000 uV Distortion Mono at 65 dBf 1000 uV 100 Hz 1000 Hz 6000 Hz Distortion Stereo at 65 dBf 1000 uV 10 8 dBf 1 9 uV 17 3 dBf 4 0 uV 37 2 dBf 40 uV 9 8 dBf 1 7 nV 1000 Hz 6000 Hz Distortion Mono and Stereo atib0 dRi uieting TH HS ais aa BN e 0 6 Hum and Noise at 65 dBf 1000 uV MA Qa A tarar DO bon ar O AI I 70 dB Frequency Response 30 Hz to 15 kHz I ei 4 ERO TE AI 0 2 2 0 dB RETRED 5 KN ANIA NR yo Oo Roa 2 0 dB Capture Ratio avib REL TORVT ka E Wa Ga aa WE a On sista Vora SARA ats Walser NN S 1 5 dB ALGO a NGGUNNMAKE T dle 1 0dB
6. perfect condition If the unit is damaged or fails to operate imme diately notify your dealer If the unit was shipped to you directly notify the transportation com pany without delay Only you the consignee may institute a claim against the carrier for ship ping damage Save the carton and all packing material as evidence of damage for their inspec tion Should assistance be required the Marantz Company will cooperate fully in assisting your claim Please fill out and mail the Warranty Registration Card within ten days of purchase The card will remain on file at the Marantz Company for the duration of the warranty period We also strongly advise that you retain your sales receipt to pro vide proof of purchase in the event that warranty service is sought TABLE OF CONTENTS Preparation for Use Rear Panel Connections Phono Inputs Tape Jacks Tape 1 In Tape 2 In Tape 1 amp 2 Out Aux Inputs FM Antenna AM Antenna FM Quadradial Output Jack Pre Out and Main In Jacks Speaker Systems Speaker Phasing Connection to AC Outlet Convenience Outlets AC Protector Fuse Simplified Operating Procedures Main Controls and Switches Power Switch Selector Switch Volume Control Balance Control Bass Mid and Treble Controls Tuning Meter Gyro Touch Tuning Control AM FM FM 254S Switch System 1 Spkr System 2 Switches Phones Jack FM Muting Switch Loudness Switch Hi Filter Switch Mono Switch Tape 1 Monitor Swit
7. reception in weaker signal areas Three single wires are required to make an AM outdoor antenna First connect one end of a single wire to the AM ANTENNA terminal on the rear panel and the other end to a very high horizontal antenna wire of 25 to 75 feet in length suspended between insulators in an out door location the higher the better Next con nect the third single wire between the G terminal of your Model 2252 and an authenti cated earth ground such as a metal water pipe 2 SPEAKER SYSTEM 1 SPEAKER SYSTEM 2 FM QUADRADIAL OUTPUT JACK In anticipation of future four channel quadrapho nic broadcasting your Model 2252 is equipped with an FM QUADRADIAL OUTPUT jack The signal available at this jack is the unequalized buffered output of the FM discriminator Its level frequency response characteristics and out put impedance are ideal to drive a four channel adaptor This jack can also be used as a simple white noise generator for checking the response characteristics of loudspeakers of amplifiers For this application connect the FM QUADRADIAL OUTPUT jack to the TAPE 1 input jack press the TAPE 1 MONITOR switch place the Model 2252 in FM mode with the muting off and tune between FM stations to receive interstation noise PRE OUT AND MAIN IN JACKS The PRE OUT jacks deliver the output of the Model 2252 preamplifier circuits to the rear panel The MAIN IN jacks are the input terminals of the po
8. the fuse holder on the rear panel and visually inspect the fuse to see if the internal con ducting filament has opened If so replace the fuse with one having the same specifications See Fuse Replacement page 11 Hrgoloni Rari gt gt man ee pala SIMPLIFIED OPERATING PROCEDURES When operating the Model 2252 Stereo Receiver for the first time follow these simple directions Later full advantage can be taken of its versatility with the remaining controls and pushswitches Step 1 Connect the FM antenna to the appro priate terminals on the rear panel Step 2 Connect the speakers to the SYSTEM 1 speaker terminals Step 3 Place all pushswitches in the out posi tion Step 4 Turn the VOLUME control all the way to the left counterclockwise and set the balance control in center position Step 5 Rotate TREBLE MID and BASS con trols to the 12 o clock position each pair of pointers to dot Step 6 Depress the SYSTEM 1 speaker push switch Step 7 Apply system power by depressing the POWER switch Step 8 Select the desired program source by set ting the SELECTOR switch to the ap propriate position If FM or AM is select ed rotate the Gyro Touch TUNING knob until the desired station is tuned Adjust the volume control to a comfort able listening level Figure 5 Front Panel Controls and Jack MAIN CONTROLS AND SWITCHES POWER SWITCH The POWER switch when depr
9. The inputs to the tape recorder in this application must be properly calibrated beforehand according to the procedure detailed in the Dolby unit s in struction booklet To achieve proper calibration it is necessary that the record level control on the Dolby unit be adjusted to the proper Dolby level by use of the reference tone transmitted by the FM station For monitoring purposes connect the Dolby unit between the line outputs of the tape recorder and the TAPE IN jacks on the 2252 When using a tape recorder containing a built in FM 254S de emphasis circuit a better signal to noise ratio can be achieved by using only the FM 25yS circuit in the Model 2252 instead of the facilities in the tape recorder Do not use both de emphasis circuits simultaneously TECHNICAL DESCRIPTION GENERAL Figure 7 is a block diagram of the Model 2252 Receiver showing the main functional elements and input and output signal routing For clarity only the left audio channel is shown the right audio channel is identical The MONO switch is common to both channels All audio controls are ganged to their counterparts in the right channel FM FRONT END FM antenna signals are applied through the an tenna coil to the dual gate MOSFET RF ampli fier The signals from the RF amplifier are fed through the tuned RF tank circuit to the mixer stage where the carrier frequency is converted to the 10 7 MHz intermediate frequency It is then fed to the in
10. Then rotate the GYRO TOUCH TUNING knob slightly back and forth until the maximum reading is obtained on the SIGNAL STRENGTH Meter The TUNING Meter is not used for AM FM Switch the SELECTOR to FM and tune to the desired station Then slowly rotate the GYRO TOUCH TUNING knob back and forth until maximum reading is obtained on the SIGNAL STRENGTH Meter and the TUNING Meter points to the center scale position The multiplex section of the Model 2252 is equipped with elec tronically triggered circuits which mute inter station noise and automatically switch to the proper mode of operation for stereo and mono phonic FM broadcasts In addition the STEREO indicator light automatically indicates a stereo broadcast Figure 6 Stereophone Plug FM 254S SWITCH To listen to a Dolbyized FM broadcast connect a Dolby noise reduction adaptor between the TAPE 1 OUT and IN jacks on the rear panel of the Model 2252 Depress the FM 25uS pushswitch and depress the TAPE 1 MONITOR switch With the FM 254S switch in the audio output signals are preset internally to standard Dolby level and the de emphasis time constant applied to the signals is also switched to 25usec automatically SYSTEM 1 SPKR SYSTEM 2 SWITCHES These switches select the loudspeaker terminals to which audio power is fed Either the SYSTEM 1 or the SYSTEM 2 stereo pair of loudspeakers may be operated individually or simultaneously if both switches are depressed
11. When the two SYSTEM 1 SPKR SYSTEM 2 switches are in the normal out position all loudspeaker terminals are internally disconnected from the power ampli fier section The signal at the headphones jack is not affected by the SYSTEM 1 SPKR SYSTEM 2 switches The out position allows private listening when stereo headphones are used NOTE Volume level should be reduced to minimum when switching speakers PHONES JACK This jack accepts headphones utilizing a standard three conductor phone plug see Figure 6 It is internally connected to the power amplifier sec tion through isolation resistors to provide ade quate sound level with popular low impedance headphones as well as with high impedance units Two or more sets of headphones may be used with the aid of Y connectors However output level will drop as additional headphones are added The headphone jack output is not affected by the SYSTEM 1 SPKR SYSTEM 2 switches FM MUTING SWITCH When tuning to FM broadcasts with the MUTING switch in its in position the muting circuit will eliminate interstation noise To prevent muting very weak stations along with the noise the muting action may be switched off by releasing the MUTING pushswitch LOUDNESS SWITCH The LOUDNESS switch compensates for human hearing characteristics by boosting the bass and treble response at low volume levels to achieve a more pleasing tonal balance HI FILTER SWITCH Thi
12. a one transistor audio amplifier which ampli fies the detected audio signals A two section variable capacitor is used to tune the antenna and mixer stages The ceramic filters utilized in the AM IF amplifier are designed for high selectivity and wide bandwidth for interference free high quality AM reception Following the AM IF amplifier the AM detector recovers the audio modulation and presents this signal to the audio amplifying stage and the mode selector switch The AM tuner and IF amplifier are subjected to the action of an effective automatic gain control circuit which maintains a constant volume level for all stations in the AM band SELECTOR SWITCH The Model 2252 has the capability to operate from a variety of program sources such as AM or 8 FM broadcasts turntable PHONO tape player or any other source capable of providing 200 mV output level AUX The SELECTOR switch con nects the inputs of the TONE control amplifier to the desired source TAPE 1 MONITOR SWITCH The TAPE 1 MONITOR switch selects between source and TAPE 1 INPUT jacks When the TAPE 1 MONITOR switch is in its normal out posi tion the preamplifier receives its input from the SELECTOR switch When the TAPE 1 MONI TOR switch is depressed the preamplifier receives its input from the TAPE 1 IN jacks PHONE EQ AMPLIFIER Phono signals of up to 100 mV can be handled without overloading The equalization network provides precise equaliz
13. annel is inoperative check the loudspeaker cord of the inoperative channel for a short circuit broken wire loose connection or other fault If the loud speaker connections appear satisfactory check for a broken open shorted corroded or discon nected shielded cable between the receiver and the input equipment Check for improper setting of the BALANCE control Look for any other visible fault If no fault is noted turn off the audio system then transpose left for right the shielded source input cables at the receiver If the opposite channel becomes inoperative when turned back on then either the shielded cable or the input equipment is at fault If the same channel remains inoperative turn off power and similarly transpose the loudspeaker cords If when the system is turned on there still is no sound from the same speaker system then either the loudspeaker system or the loudspeaker cord is at fault If the opposite speaker system fails to operate then the receiver is inoperative Refer the problem to your nearest authorized Marantz Service Facility I M Distortion 1 H F method 60 Hz and 7 kHz mixed 4 1 at rated power output at 8 ohm load impedance at 4 ohm load impedance Damping Factor at 20 Hz Sensitivity at MAIN IN Impedance at MAIN IN Frequency Response for Power Amp Only at 1 Watt output 20 Hz to 20 kHz Preamplifier Section Phono Input Overload at 1 kHz Equivalent Input Noise Dynamic
14. ation to the RIAA stand ard and sets the voltage gain of the phono pre amplifier to 40 dB at 1 kHz MONO FUNCTIONS When the MONO pushswitch is in the in posi tion the two channels are connected together through mixing resistors In addition the left and right channel tape input signals are connected together through the same resistor network This facility allows all inputs to be converted to the monophonic mode CONTROL CIRCUITS The control circuits portion of the Model 2252 consists of the BALANCE VOLUME BASS MID TREBLE and HI FILTER controls All controls affect the left and right channels simulta neously However the BASS MID and TREBLE controls have clutched sections which allow indi vidual adjustment of tonal balance for each channel With the controls set for flat response and volume control at maximum the overall volt age gain from any high level input to the loud speaker terminals is approximately 41 dB BALANCE CONTROL The BALANCE control is a full range control which permits attenuation of each channel to cutoff The change of attenuation in each channel as the control is moved from center has been designed to maintain total apparent loudness from both channels This feature makes it a true stereo balance control VOLUME CONTROL The VOLUME control attenuates both channels simultaneously and maintains tracking to within 3 dB at any point of attenuation to 60 dB from maximum Since the cont
15. ch m BAAOOVOUNNN AA hh h h ddd O 0 0 Tape Recording and Dubbing Recording Dubbing Recording Dolbyized FM Programs Technical Description General FM Fron End FM IF Amplifier FM Stereo Demodulator Muting Circuit AM Tuner Selector Switch Tape 1 Monitor Switch Phono EQ Amplifier Mono Functions Control Circuits Balance Control Volume Control Tone Control Amplifier Amplifier Maintenance Cleaning Fuse Replacement In Case of Difficulty General Specifications Service Notes Repairs Repacking for Shipment NNNN O O O O O to O CO CI 0 0 0 09 00 0000 11 14 14 14 LIST OF ILLUSTRATIONS Rear Panel Connection Facilities AM FM Antenna Connection AM Ferrite rod Antenna Front Panel Controls and Jack Stereophone Plug Functional Block Diagram Packing Instructions OO a Loudspeaker System Connections BODMWNN PREPARATION FOR USE Figure 1 shows the location of input and output jacks on the rear panel These jacks are for per manent connections Front panel jacks and their use will be discussed later All connections to the rear panel should be made with the power to the entire system turned off The rear panel signal connections are arranged in stereo pairs All signal connections to the Model 2252 with the exception of the FM antenna and loudspeakers should be made with shielded audio cables To avoid confusion connect one cable at a time between the 2252 and the other compo
16. een speakers and am plifier Use caution when connecting your Model 2252 to a loudspeaker with built in power supply such as an electrostatic loudspeaker The common connection terminal of such a speaker may be capacitively coupled to ground through its own power supply To protect the Model 2252 from distortion and possible overload make sure the terminals of the Model 2252 are connected to the common terminals of such a loudspeaker system CAUTION NEVER DIRECTLY CONNECT THE LOUDSPEAKER TERMINALS OF ONE CHANNEL IN PARALLEL WITH THOSE OF ANY OTHER ANY RESULTING DAMAGE IS NOT COVERED UNDER WARRANTY NOTE Do not use 4 ohm speakers if main and remote speakers are to be used simul taneously Use 8 or 16 ohm speakers only CONNECTION TO AC OUTLET With the front panel POWER pushswitch OUT plug the line cord into an electrical outlet supply ing the proper voltage CAUTION DO NOT PLUG YOUR MODEL 2252 INTO A DC OUTLET AS SERIOUS DAMAGE WILL OCCUR CONVENIENCE OUTLETS One UNSWITCHED and one SWITCHED AC OUTLET are provided on the rear panel for pow ering associated components of your system tape recorder record player etc AC PROTECTOR FUSE This feature automatically disconnects AC power in the event of a power source or circuit overload If the POWER pushswitch is activated and the front panel fails to illuminate and no sound is heard through the speakers turn off the power and unscrew
17. elded cable consists of two inner conduc tors plus an outer shield and insulating jacket This type of shielded cable effectively prevents the lead in from contributing multipath distor tion For rural areas it is recommended that a local dealer be consulted about antenna installation and lightning arrestor protection Master antenna systems are not recommended for use with your Figure 3 AM Ferrite rod Antenna Model 2252 such systems are usually designed expressly for television reception and frequently suppress FM signals before distribution In addi tion master antenna systems often severely re duce the quality of the FM signal Where outdoor antennas are prohibited or inconvenient place the antenna in vacant attic space or use a simple 300 ohm TV rabbit ear antenna or the ribbon type folded dipole antenna supplied with the Model 2252 Both are practical and will give satisfactory results in primary signal areas Figure 2 shows connection methods for various antennas If 75 ohm cable is desired we recom mend using the type with an F type connector terminal attached to the cable This is the easiest type of cable to connect and disconnect AM ANTENNA Your Tuner is equipped with an AM ferrite rod antenna BEFORE USING THE MODEL 2252 SWING THE ANTENNA OUT AS SHOWN IN FIGURE 3 The ferrite rod antenna will give you satisfactory results in primary signal areas However an out door antenna will provide better
18. essed supplies AC power to the Model 2252 and to the SWITCHED outlet on its rear panel SELECTOR SWITCH The SELECTOR switch selects the program source for listening or recording If a tape re corder s playback output has been connected to the TAPE 2 IN jacks on the rear panel you can select tape listening by rotating the SELECTOR SWITCH to the TAPE 2 position VOLUME CONTROL The VOLUME control adjusts the level of both output channels simultaneously while maintain ing stereo balance at all normal settings lt does not effect the recording outputs BALANCE CONTROL This control alters the level of either output chan nel in situations where it is necessary to correct unbalanced programs sometimes encountered in older stereo recordings or in stereo broadcasts As it is moved from its center position it decreases the level in one output channel while maintaining the level in the other channel BASS MID AND TREBEL CONTROLS These controls are used to adjust the tonal bal ance of program material to suit individual listen ing preference TUNING METER The Model 2252 is equipped with two meters a SIGNAL STRENGTH Meter and a TUNING Meter 1 The SIGNAL STRENGTH Meter indicates the signal strength of any AM or FM broadcast 2 The TUNING Meter operates on FM only and indicates correct center tuning of the station GYRO TOUCH TUNING CONTROL AM Switch the SELECTOR to AM and tune to the desired station
19. ficulty call the toll free tele phone number listed on the back of the Warranty to obtain the name and address of the Marantz Authorized Service Station nearest your home or business In many cases the dealer where you purchased your Marantz unit will be equipped to provide service REPACKING FOR SHIPMENT Should it become necessary to repack your Model 2252 for shipment to the factory to an authoriz ed service station or elsewhere please observe the following precautions Do not ship the unit installed in its accessory walnut cabinet remove the unit from the cabi net before packing Pack the unit carefully using the original material as shown in Figure 8 PLEASE NOTE that if you have discarded lost or damaged the packing material new packing material may be obtained by writing to the Marantz Technical Service Department The carton its fillers and packing instructions will be returned to you at a nominal charge Ship via a reputable carrier do not use Parcel Post and obtain a shipping receipt from the carrier Insure the unit for its full value Be sure to include your return address on the shipping label Figure 8 Packing Instructions 14 PRINTED IN JAPAN The Sound of Marantz is the compelling warmth of a Stradivarius It is a dancing flute a haughty bassoon and the plaintive call of a lone French horn The Sound of Marantz is the sound of beauty and Marantz equipment i
20. hem are printed in BOLD FACE TYPE exactly as they appear on the front and rear panels of your Receiver AC Line Operation WARNING TO PREVENT FIRE OR SHOCK HAZARD DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE GENERAL DESCRIPTION The Marantz Model 2252 is an all solid state receiver incorporating the innovative design and unparalleled technology that have made Marantz famous in the audio component industry The Model 2252 features a sensitive stereo FM tuner a highly selective AM tuner and a low dis tortion preamplifier and amplifier on a single chassis The FM tuner features a front end which employs a dual gate MOSFET and FM IF unit a phase locked loop multiplex decoder and an AM tuner all of which utilize IC s throughout The amplifier sections permit the connection of two stereo pairs of loud speakers a turntable or record changer two tape recorders stereo head phones and an auxiliary source such as an addi tional tuner or a TV sound source AFTER UNPACKING It is advisable to retain all original packing mate rial to prevent damage should you wish to trans port or ship the Model 2252 refer to page 14 for repacking and shipping instructions Be careful that you do not inadvertently throw away or lose the parts packed with the unit Please inspect your Model 2252 carefully for any signs of shipping damage Our very strict quality control and professional pride ensure that each Model 2252 left the factory in
21. is placed in the TAPE 2 posi tion and the TAPE 1 MONITOR switch is re leased In addition these jacks allow tape copying from TAPE 2 to TAPE 1 The resulting recording can be monitored by depressing the TAPE 1 MONITOR pushswitch TAPE 1 amp 2 OUT Connecting these jacks to the line inputs of a tape recorder permits recording from the program source indicated by the SELECTOR switch The an coaxial cable SP connector Figure 2 AM FM Antenna Connection signals available at this pair of jacks are not affected by the BALANCE VOLUME TREBLE BASS HI FILTER LOUDNESS and MONO pushswitches on the front panel AUX INPUTS The AUX INPUT jacks are for miscellaneous high level signal sources such as additional tuners and or receivers tape players phonographs that provide RIAA equalized high level output TV sound outputs and other external components FM ANTENNA The best FM reception is obtained with a Log Periodic type antenna mounted on a good quality rotor system For fringe areas Marantz recom mends a Log Periodic antenna with six or more elements designed expressly for FM reception To minimize local noise and multipath picked up by the lead in wires use a balanced and shielded 300 ohm cable or a coaxial 75 ohm cable with a 300 to 75 ohm matching transformer at the antenna Unshielded lead in acts as an omni directional antenna and can cancel the direc tional benefits of your antenna Low loss 300 ohm shi
22. nput thus allowing you to listen to the signal being recorded before and after recording This switch is also known as the TAPE SOURCE switch TAPE RECORDING AND DUBBING RECORDING The program source selected by the SELECTOR switch may be recorded on to either tape record er When the SELECTOR is set to TAPE 2 how ever the TAPE 2 OUT JACKS are muted to pre vent feedback oscillations that would occur if tape recorder 2 were inadvertently placed in the record mode DUBBING A tape played on tape recorder 2 may be copied on to tape recorder 1 Set the SELECTOR switch to TAPE 2 To monitor tape 1 as it is being re corded depress the TAPE 1 MONITOR switch To monitor the source which is in this case tape 2 release TAPE 1 MONITOR switch Either tape or source can be monitored without disturbing the actual recording process RECORDING DOLBYIZED FM PROGRAMS Dolbyized FM broadcasts contain Dolbyized audio information to which a special pre emphasis is applied for the purpose of improving the noise reduction process To make a Dolbyized tape re cording of such broadcast depress the FM 25uS switch to properly de emphasize the signal but bypass the noise reduction adaptor to record the Dolbyized audio directly onto the tape This can be done by switching the Noise Reduction switch to OFF if the Dolby adaptor is so equipped or by connecting the TAPE OUT jacks of the 2252 directly to the LINE IN jacks of the tape deck
23. put of the IF amplifier Careful attention to the thermal and electrical characteristics of the local oscillator has mini mized drift thus eliminating the necessity for AFC FM IF AMPLIFIER The FM IF amplifier system is composed of one IC expressly developed for FM IF use plus one transistor and three dual element ceramic filters The IC includes a complete IF amplifier limiter stages FM discriminator and a 6 stage double ended type differential amplifier providing excell ent AM rejection The FM discriminator stage is composed of a double balanced type quadrature detector circuit The signal from the front end is fed to the IC through the 3 ceramic filters and the one transis tor amplifier The characteristics of these filters are ideal in that the 200 kHz passband is phase linear with sharp cutoff slopes Its exceptional phase linearity as sures the elimination of a major source of high frequency distortion and a loss of stereo separa tion The sharp cutoff slopes provide outstanding selectivity permitting reception of closely space stations FM STEREO DEMODULATOR The stereo composite signal obtained from the quadrature detector is fed to the MPX IC The L and R signal outputs from the MPX IC are applied through the low pass filter and the de emphasis circuit to the one per channel transistor ampli fier The output about 1100 mV obtained from this amplifier is fed to the L and R output ter minals at the rea
24. r panel through the function switch This stereo demodulating IC employs a PLL Phase Locked Loop technique whereby the phase of the 38 kHz switching carrier signal in the decoder is constantly interlocked with the phase of the 19 kHz input pilot signal Phase shift of the switching carrier 38 kHz is thereby eliminated and deterioration of separation and distortion does not occur 19 kHz and 38 kHz muting circuits are not em ployed so that stability is greatly improved Mut ing distortion as a result of element aging or adjacent temperature changes is consequently eliminated The stereo demodulating 38 kHz carrier switching signal is very clean with no even harmonic con tent SCA rejection of approximately 80 dB is obtained since resonant beats are not generated between the secondary harmonic 76 kHz of the 38 kHz carrier switching signal and the SCA signal 67 7 kHz MUTING CIRCUIT If there are no signals present any FM tuner will generate some noise The muting circuit elimi nates this noise In addition spurious noise that is generated while tuning is also removed The mut ing circuit in the Model 2252 is integrated into the IF stage The circuit is also designed to mini mize popping noises which tend to be generated when muting is switched in and out AM TUNER The AM tuner section of the Model 2252 is com posed of an IC incorporating an RF amplifier local oscillator mixer IF amplifier and detector and
25. rol is situated at the in put of the tone amplifier there is no possibility of overloading the amplifier stages under maxi mum rated output conditions Thus distortion is kept to a minimum After attenuation by the BALANCE and VOLUME controls the signal is applied to the tone control amplifier TONE CONTROL AMPLIFIER The TONE CONTROL AMPLIFIER s circuitry uses a continuously variable negative feedback type configuration for lowest distortion The signal from the TONE CONTROL AMPLIFIER feeds the HI filter circuit when the HI FILTER is activated AMPLIFIER The amplifier section of the Model 2252 is a direct coupled full complimentary circuit It utilizes current limiting and thermal compensa tion circuits to provide safe highly stable operat ing conditions The silicone output devices used in the power amplifier section provide a large collector dissipation margin oL ares iw tarea our ares our 019 Oo 9 d A TE rus En resus ES murino Pre ser murino ADI AM ne tever ose PHONO AMP VOLUME nea TONE cont E rien SELECTOR NETWORK BALANCE FROM Lovoness OTHER CH cont Sonne K S LOUDNESS Y 0000 H speaken SE Figure 7
26. rs are correctly phased perform the follow ing test 1 Complete the necessary signal connections so that program material may be played through the speakers 2 Place the speakers in the center of the room 3 Depress the MONO pushswitch and play a re cord or radio or tape with strong bass tones at a low volume level Center the BALANCE control 4 Position the speakers about six inches apart face to face Listen particularly to the appar ent loudness of the bass tones 5 Next turn off all power but do not disturb the VOLUME or BALANCE settings Reverse the connections on the right speaker only Turn on the power and listen again If the bass tones now seem louder than in 3 you have correct ed the phasing between the speakers If the bass notes now sound softer turn off the power and reconnect the speakers as they had been originally 6 If an additional pair of speakers is used along with the main speaker system check phasing between the remote speakers and the main speakers Use the BALANCE control to play only two speakers at once and invert the wiring on the remote speakers as necessary Do not change the connections on the main speaker system 7 Once having phased all speakers you need not repeat this procedure in the future if you now mark the speaker connections and or cables Any method of coding is satisfactory provided it enables you in the future to duplicate your now correct hookup betw
27. s designed to bring you the subtle joy of its delight Wonderful adventures in sound await you when you discover that the Sound of Marantz is the sound of music at its very best DOLBY is a trademark of Dolby Laboratories Inc 2208851010 NIZ ZW haa A Hen BPE 27
28. s switch can be used to reduce high frequency noise such as that associated with the playing of poorly recorded tapes or worn disc recordings When the AM tuner is being used this switch will help to suppress considerably the high pitched whistle caused by adjacent AM channel inter ference This filter will also along with high fre quency noise slightly attenuate high frequency program material and should therefore be used judiciously MONO SWITCH When a marginal stereo signal is received random noise and phase modualtion may cause the tuner s multiplex circuitry to trigger the STEREO mode intermittently In this case it is sometimes desir able to cancel the multiplex operation entirely in favor of obtaining a more listenable signal The MONO switch performs this function and con verts all output signals to the MONOPHONIC mode While playing a single channel source such as TV or AM depress the MONO pushswitch to hear the source through both speakers When playing a monophone phonograph record use this push switch to suppress rumble record surface noise and pinch effect distortion TAPE 1 MONITOR SWITCH When this pushswitch is out the program being recorded and heard is determined by the setting of the SELECTOR switch With the TAPE 1 MONITOR pushswitch in the amplifier input connections are switched to the output of the tape recorder without affecting the signal pre sented to the tape recorder s i
29. wer amplifier section of the Model 2252 The PRE OUT and MAIN IN jacks are bridged internally by special contacts within the jack assembly When you wish to use such equipment as a graphic equalizer compressor limiter or expander you may connect these instruments to your Model 2252 with appropriate lengths of shielded audio cables When the external equip ment is connected the insertion of its RCA phono plugs in to the MAIN IN jacks automatical 3 Figure 4 Loudspeaker System Connections ly breaks the internal connections to prevent the external equipment from being bypassed SPEAKER SYSTEMS The SPEAKER SYSTEMS terminals on the rear panel can accommodate two stereo pairs of loud speakers Connect the main pair to the SYSTEM 1 terminals The SYSTEM 2 terminals are for a second stereo pair of loudspeakers see Figure 4 Selection of loudspeaker systems is made with the SYSTEM 1 SPKR SYSTEM 2 pushswitches on the front panel To connect the speakers to the 2252 use ordina ry 18 gauge two conductor lamp cord For dis tances longer than 30 feet use 16 gauge wire or heavier SPEAKER PHASING To assure the best stereo separation and frequen cy response the speakers must be properly phased The positive terminal on each speaker should be connected to its respective terminal on the Model 2252 and the negative or common terminal should be connected to its respective terminal To verify that a pair of speake

Marantz-2252-Owners-Manual

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